Return a*b+c (mod L)
pub fn mulAdd(a: CompressedScalar, b: CompressedScalar, c: CompressedScalar) CompressedScalar
pub fn mulAdd(a: CompressedScalar, b: CompressedScalar, c: CompressedScalar) CompressedScalar { return Scalar.fromBytes(a).mul(Scalar.fromBytes(b)).add(Scalar.fromBytes(c)).toBytes(); }